JP3179873B2 - Ink supply unit for stencil printing machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink supply device for a stencil printing machine.

[0002]

2. Description of the Related Art An ink supply device of a stencil printing machine has a roller type or blade type squeegee member extending in the axial direction of a rotationally driven plate cylinder and slidingly contacting the inner peripheral surface of the plate cylinder. The squeegee member is configured to supply printing ink in an ink reservoir formed by extending in the axial direction of the plate cylinder to the plate cylinder by soaking. Nos. 55-55889 and JP-A-3-240584.

[0003]

In general stencil printing, printed images rarely exist in the full width direction of the paper, and in many cases, margins exist in both width portions of the paper. .

For this reason, in the ink supply device as described above, the printing ink in the central portion in the axial direction of the plate cylinder in the ink reservoir is consumed early, but is present in both end regions in the axial direction of the plate cylinder. A phenomenon occurs that the printing ink is hardly consumed.

[0005] If the printing ink in the central region in the axial direction of the plate cylinder in this ink reservoir is consumed a lot, and the consumption of the printing ink in the both end regions in the axial direction of the plate cylinder is small,
The amount of ink existing in the ink reservoir at both end regions in the axial direction of the plate cylinder is larger than the amount of ink in the central region in the axial direction of the plate cylinder, and the printing ink existing in the both end regions in the axial direction of the plate cylinder. Flows laterally to both end regions in the axial direction of the plate cylinder.

However, the lateral flow of the printing ink does not catch up with the difference between the ink consumption in the two areas, so that the amount of ink present in the axially opposite end regions of the plate cylinder is smaller than the amount of ink in the axially central region of the plate cylinder. The phenomenon that increases by this is not eliminated.

In this case, the printing ink existing in the ink reservoir at both end regions in the axial direction of the plate cylinder, in other words, the printing ink existing at both end regions of the ink reservoir, stagnates in this region. Therefore, the ink is not consumed for a long time and remains in the ink reservoir. Therefore, if the printing ink is of an emulsion type in particular, this printing ink causes a change in the state of the emulsion and reduces the viscosity,
This causes a property change that softens.

[0008] The softening of the printing ink causes deterioration of the quality of the printed image due to bleeding of the printed image and the like, and when the printing ink in the ink reservoir is softened, the printing ink easily flows to the outside from the ink reservoir. .

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems in the conventional ink supply apparatus, and prevents the printing ink existing in both end regions of the ink reservoir from being consumed for a long time. It is another object of the present invention to provide an ink supply device for a stencil printing apparatus which always performs printing with stable image quality and does not cause a problem such as a printing ink flowing out from an ink reservoir to the outside.

[0010]

Above-mentioned object, according order to achieve the above, according to the present invention, the squeegee member extending in the axial direction of the plate cylinder is rotated in sliding contact with the inner circumferential surface of the plate cylinder, the squeegee A member having an ink reservoir formed to extend in the axial direction of the plate cylinder, and an ink for a stencil printing machine configured to supply printing ink accumulated in the ink reservoir to the plate cylinder by soaking. in the supply device, the place of the ink reservoir portion
An ink suction path having an ink suction port disposed at a fixed position,
In a different position with respect to the axial direction of the ink suction port and the plate cylinder
An ink discharge path in which ink discharge ports are arranged;
Ink circulation pump in which the ink path and ink path are connected
And the ink circulation pump prints the ink pool
Suction ink from the ink suction port and discharge from the ink discharge port
Circulates the printing ink in the ink reservoir.
Or ink suction above the ink reservoir
An ink suction path in which a port is arranged, and the ink suction port and the plate cylinder
Ink outlets at different positions in the axial direction
Ink discharge path, the ink suction path and the ink discharge path
And an ink circulation pump connected to the
Circulation pump sucks the printing ink in the ink reservoir
Ink supplied from the ink supply device by suction from the mouth
This is achieved by an ink supply device for a stencil printing machine characterized by maintaining a substantially constant amount of printing ink in a reservoir .

[0011]

According to the above arrangement, the predetermined amount of the ink reservoir is determined.
By arranging the ink suction port at the position, the ink circulation pump sucks the printing ink in the ink pool from the ink suction port and discharges this printing ink from the ink discharge port to the ink pool. Some printing ink circulates. Also, ink is absorbed in the upper part of the ink reservoir.
Arrange the ink inlet and print in the upper layer from the ink suction port.
Squeeze the key to regulate the amount of printing ink in the ink reservoir
As a result, the printing ink in the ink reservoir comes into contact with this
Rollers (for example, the squeegee roller 11 of FIG. 1 or the plate of FIG. 5)
The body 1) constantly rotates in a spiral shape by rotation. Such an inn
There is circulation or spiral rotation of the printing ink in the ink reservoir
Then, the printing ink does not stay in the ink reservoir.
And always send fresh printing ink to the printing department,
Printing ink will be consumed.

[0012]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of an embodiment of the present invention.

FIGS. 1 and 2 show an embodiment of an ink supply device for a stencil printing apparatus according to the present invention. In these figures, reference numeral 1 denotes a cylindrical plate cylinder.
Is made of an ink-permeable material such as a porous metal plate or a mesh structure.

The plate cylinder 1 is wound around a stencil sheet (not shown) around the outer peripheral surface thereof, and is rotated counterclockwise in the figure around its own central axis by a plate cylinder rotation driving means (not shown). The printing paper (not shown) is rotated and pressed in a rotating state against a stencil sheet on the outer peripheral surface of the plate cylinder by a press roller 3 to perform stencil printing on the printing paper.

A staple-shaped squeegee support frame 5 is fixedly arranged in the plate cylinder 1. The squeegee support frame 5 includes a pair of side plate portions 7 located on both axial sides of the plate cylinder 1.
The squeegee roller 11 is rotatably supported by the center shaft 9 therebetween.

The squeegee roller 11 extends in the axial direction of the plate cylinder 1 and slides on the inner peripheral surface of the plate cylinder 1. The squeegee roller 11 includes a sprocket 13 attached to the center shaft 9 and a timing belt 15 engaged with the sprocket 13. It is driven to rotate counterclockwise in synchronization with the rotation of the plate cylinder 1.

The squeegee support frame 5 supports the doctor rod 17 between the side plates 7 in parallel with the squeegee roller 11 and with a predetermined ink outflow gap 19 with respect to the outer peripheral surface of the squeegee roller 11.

Printing ink is supplied to the outer peripheral surface of the squeegee roller 11 from an ink supply pipe 21.
An ink reservoir P is formed on the squeegee roller 11 by the printing ink 7 from the ink supply pipe 21 with the dam 7 as a weir.

An ink circulation pump 23 is attached to the squeegee support frame 5. Ink circulation pump 23
Is constituted by, for example, a small gear pump and is driven by a motor 25.

The ink circulation pump 23 has a suction hose 27
(Ink suction path) and a discharge hose (ink discharge path) 29 are connected. The suction hose 27 is branched into two,
Each tip extends on both sides in the axial direction of the plate cylinder 1 and faces the upper part of the ink reservoir P on both sides in the axial direction, and forms ink suction ports 31 respectively. This ink suction port 31
When the amount of ink in the ink reservoir P is equal to or less than a predetermined value, the vertical position of the ink reservoir P is separated from the printing ink in the ink reservoir P as shown in FIG.

The discharge hose 29 extends to the center of the plate cylinder 1 in the axial direction, and faces the upper portion of the ink reservoir P at the center in the axial direction to form an ink discharge port 33.

A current detector 35 is provided in the power supply circuit of the motor 25.
Is attached, and the current detector 35 detects the value of the current supplied to the motor 25. The energizing current value of the motor 25 detected by the current detector 35 is input to the current value determination circuit 37.

The current value judging circuit 37 compares the supplied current value from the current detector 35 with a predetermined comparison reference value. If the supplied current value is equal to or greater than the comparison reference value, the ink in the ink reservoir P An ink amount detection signal indicating that the amount is equal to or more than a predetermined value is generated, and if the supplied current value is not equal to or greater than the comparison reference value, the ink amount indicating that the ink amount in the ink reservoir P is equal to or less than the predetermined value. A detection signal is generated.

According to the above configuration, the motor 25 drives the ink circulation pump 23 to rotate, and the ink circulation pump 23 drives the ink suction port 31 to generate a suction force. At this time, if the amount of ink in the ink reservoir P is equal to or greater than a predetermined value, the ink suction ports 31 come into contact with the printing ink in the ink reservoir P at both sides in the axial direction of the plate cylinder 1, Aspirate the printing ink present on both sides. The printing ink sucked into the ink suction port 31 flows through the suction hose 27 and reaches the ink circulation pump 23, thereby flowing through the discharge hose 29, and is discharged from the ink discharge port 33, and is discharged from the ink discharge port 33 in the axial center of the plate cylinder 1. Is returned to the ink reservoir P.

Due to the flow of the printing ink by the ink circulation pump 23, the printing ink in the ink reservoir P is transferred to the plate cylinder 1.
Circulating in the axial direction of the plate cylinder 1, so that the printing ink existing in the axially opposite end regions of the plate cylinder 1 in the ink reservoir P is prevented from being consumed for a long time.

As described above, when the ink circulation pump 23 is sucking the printing ink from the ink suction port 31, the pump driving load of the motor 25 is larger than when the ink is sucking the air. The energizing current value of the motor 25 detected by the detector 35 is equal to or greater than the comparison reference value in the current value judging circuit 37.

Therefore, at this time, the current value judgment circuit 37
By comparing the current carrying value from the current detector 35 with the comparison reference value, it is determined that the current carrying value is greater than or equal to the comparison reference value,
An ink amount detection signal indicating that the amount of ink in the ink reservoir P is equal to or greater than a predetermined value is generated.

When the printing ink in the ink fountain P is consumed and the amount of ink falls below a predetermined value, the ink suction port 31
Is separated from the printing ink in the ink reservoir P and sucks air. At this time, the pump driving load of the motor 25 is smaller than when the ink circulation pump 23 is sucking the printing ink from the ink suction port 31. Therefore, the current flowing through the motor 25 detected by the current detector 35 is reduced. The value becomes equal to or less than the comparison reference value in the current value judgment circuit 37, and the current value judgment circuit 37 compares the energization current value from the current detector 35 with the comparison reference value and determines that the energization current value is equal to or less than the comparison reference value. By making a determination, an ink amount detection signal indicating that the amount of ink in the ink reservoir P is equal to or less than a predetermined value is generated.

At this time, the control for supplying the printing ink from the ink tank (not shown) to the ink reservoir P from the ink supply pipe 21 may be performed in a known manner.

In the above embodiment, the suction hose 27
Are forked so as to suck the printing ink from both sides in the axial direction of the plate cylinder 1 and to return the printing ink to the central portion in the axial direction of the plate cylinder 1. In addition to this, as shown in FIG. As shown, the suction hose 27 extends to one side of the plate cylinder 1 in the axial direction, the ink suction port 31 is disposed only on one side in the axial direction, and the discharge hose 29 is connected to the plate cylinder 1 in the axial direction. Even if the ink discharge port 33 is arranged on the other side in the axial direction extending to the other side, as shown in FIG. 4, the suction hose 27 is connected to one side of the plate cylinder 1 in the axial direction. To the ink suction port 31 only on one side in this axial direction.
May be disposed, and the ink discharge port 33 of the discharge hose 29 may be disposed in a substantially central region of the plate cylinder 1 in the axial direction.

In each case, the ink circulation pump 23
Sucks the printing ink in the ink reservoir P from the ink suction port 31 and discharges this printing ink from the ink discharge port 33 to the ink reservoir P, whereby the printing ink in the ink reservoir P is moved in the axial direction of the plate cylinder 1. The printing ink existing in the axially opposite end regions of the plate cylinder 1 in the ink reservoir P is prevented from being consumed for a long time.

FIG. 5 shows another embodiment of the ink supply device of the stencil printing machine according to the present invention. In FIG. 5, portions corresponding to FIGS. 1 and 2 are denoted by the same reference numerals as those given to FIGS. In this embodiment, left and right squeegee support side plates 43 connected to each other by a connection shaft 41 extending along the axial direction of the plate cylinder 1 are provided in the plate cylinder 1. The squeegee blade 51 is supported in parallel with the axial direction of the plate cylinder 1 by a squeegee support board 45 stretched between them and a squeegee support mounting plate 49 fixedly mounted on the squeegee support board 49 with screws 47.

The squeegee blade 51 is made of a rubber-like elastic material such as urethane rubber.
5 and is cantilevered by the squeegee support mounting plate 49, extends in the axial direction of the plate cylinder 1, and has a free edge, which is a leading edge, pressed against the inner peripheral surface of the plate cylinder 1 at a predetermined squeegee angle.

In this case, the printing ink is supplied from the ink supply pipe 21 to the inner peripheral surface of the plate cylinder 1, and the squeegee blade 41 and the plate are rotated with the clockwise rotation of the plate cylinder 1 in the drawing. An ink reservoir P is formed on the side delayed from the contact position with the cylinder 1 in the rotation direction of the plate cylinder 1, that is, in the triangular area on the right side of the contact position as viewed in FIG.

One end of a swinging lever 53 is pivotally connected to the connecting shaft 41, and the swinging lever 53 is connected to the supporting shaft 5 having an intermediate portion attached to a fixed frame (not shown).
5, and a cam follower roller 57 is rotatably supported at the other end.

The cam follower roller 57 includes a swing lever 5
3 is urged in the counterclockwise direction in the figure by a spring 59 attached to the connecting shaft 41, thereby engaging with the cam 63 of the cam shaft 61 rotatably supported by the fixed frame. . The cam shaft 61 is driven to rotate by gears 65 and 67 in a one-to-one transmission relationship in synchronization with the rotation of the plate cylinder 1.

The other end of the squeegee support side plate 43 has a spring 6
9, the other end is fixed to the fixed frame so that the mounting angle can be adjusted.
It is in contact with 1.

Due to this contact relationship and the above-described cam mechanism, the squeegee support side plate 43 and the squeegee blade 51 accompanying the squeegee support plate correspond to the non-ink passage area of the stencil sheet clamp portion formed in a part of the plate cylinder 1. During the rotation phase section, the plate cylinder 1 is forcibly separated from the inner peripheral surface of the plate cylinder 1.

Also in this embodiment, an ink circulation pump 23 is provided, and an ink suction port 3 is provided by a suction hose 27.
1 is disposed above the ink reservoir P, the ink discharge port 33 is disposed by the discharge hose 29 at a position delayed from the ink reservoir P in the rotation direction of the plate cylinder 1, and the ink suction port 31 is controlled by the ink circulation pump 23. The printing ink in the ink reservoir P is further sucked and the printing ink is sucked into the ink discharge port 33.
The ink is further discharged toward the ink reservoir P.

Although not shown in the drawing, the ink suction ports 31 are also disposed at both end regions in the axial direction of the ink reservoir P in this case, whereas the ink discharge ports 33 are arranged in the axial direction of the ink reservoir P. It is located in the center end area.

Therefore, also in this embodiment, the printing ink in the ink reservoir P circulates in the axial direction of the plate cylinder 1 and exists in the ink reservoir P at both end regions in the axial direction of the plate cylinder 1. It is avoided that the used printing ink is not consumed for a long time.

FIG. 6 shows another embodiment of the ink supply device of the stencil printing apparatus according to the present invention. In FIG. 6, parts corresponding to those in FIG. 5 are indicated by the same reference numerals as those in FIG. In this embodiment, the discharge hose 29 is connected to the ink supply pipe 21, and the printing ink in the ink reservoir P sucked from the ink suction port 31 by the ink circulation pump 23 is sent to the ink supply pipe 21. The ink is returned from the supply pipe 21 to the ink reservoir P.

Therefore, also in this embodiment, the printing ink in the ink reservoir P circulates including the movement of the plate cylinder 1 in the axial direction, and in the ink reservoir P, both sides of the plate cylinder 1 in the axial direction. It is avoided that the printing ink present in the end areas is not consumed for a long time.

In each of the above-described embodiments, the ink circulation pump 23 is configured to be driven to rotate by the dedicated motor 25. And the printing cylinder 1 may be rotationally driven as the plate cylinder 1 rotates.

[0045]

As will be understood from the above description, according to the ink supply device of the stencil printing apparatus according to the present invention, the ink circulation pump sucks the printing ink in the ink reservoir from the ink suction port and this printing ink. Is discharged from the ink discharge port to the ink reservoir, whereby the printing ink in the ink reservoir circulates, so that the printing ink existing in the axially opposite end regions of the plate cylinder in the ink reservoir is not consumed for a long time. Is prevented, and the printing ink present in this region is prevented from deteriorating with time. In addition, ink reservoir
The upper layer of printing ink from the ink suction port located above
To regulate the amount of printing ink in the ink pool
When the printing ink in the ink reservoir is in contact with the rollers
It always rotates well in rotation, and prints in the ink reservoir.
Long-term stagnation of the ink is avoided, and the printing ink deteriorates over time.
Is prevented. As a result, when the printing ink is of the emulsion type, a decrease in the viscosity of the printing ink due to a change in the state of the emulsion is avoided, so that printing is always performed with a stable image quality. Due to this, it is possible to avoid a problem that the printing ink flows out from the ink reservoir to the outside.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of an ink supply device of a stencil printing apparatus according to the present invention.

FIG. 2 is a schematic perspective view showing an embodiment of an ink supply device of the stencil printing apparatus according to the present invention.

FIG. 3 is a schematic configuration diagram showing another embodiment of the ink supply device of the stencil printing apparatus according to the present invention.

FIG. 4 is a schematic configuration diagram showing another embodiment of the ink supply device of the stencil printing apparatus according to the present invention.

FIG. 5 is a schematic configuration diagram showing another embodiment of the ink supply device of the stencil printing apparatus according to the present invention.

FIG. 6 is a schematic configuration diagram showing another embodiment of the ink supply device of the stencil printing apparatus according to the present invention.

[Explanation of symbols]

 Reference Signs List 1 plate cylinder 3 press roller 5 squeegee support frame 11 squeegee roller 17 doctor rod 23 ink circulation pump 25 motor 27 suction hose 29 discharge hose 31 ink suction port 33 ink discharge port 35 current detector 37 current value judgment circuit 43 squeegee support side plate 53 swing Moving lever 57 Cam follower roller 63 Cam P Ink reservoir

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) B41L 13/18 B41F 31/02 B41F 31/03 B41F 31/08 B41F 31/20

Claims (3)

(57) [Claims] 1. An axially extending plate cylinder which is driven to rotate.
Squeegee member that slides on the inner peripheral surface of the plate cylinderWhen,The ski
The inner member is formed by extending the member in the axial direction of the plate cylinder.
Ki poolAnd having accumulated in the ink reservoirPrint-in
A hole configured to supply a key to the plate cylinder for soaking.
In the ink supply device of the plate printing device,An ink suction port is located at a predetermined position in the ink reservoir.
Ki suction path, Different positions with respect to the axial direction of the ink suction port and the plate cylinder
An ink discharge path with an ink discharge port Ink wherein the ink suction path and the ink discharge path are connected
And a circulation pump, The ink circulation pump supplies the printing ink in the ink reservoir.
Suction from the ink suction port and discharge from the ink discharge port
Circulates the printing ink in the ink reservoir Specially
Ink supply device for stencil printing machine. (2)Extending in the axial direction of the rotationally driven plate cylinder
A squeegee member for slidingly contacting the inner peripheral surface of the plate cylinder;
The inner member is formed by extending the member in the axial direction of the plate cylinder.
A printing ink reservoir that has a ink reservoir.
A hole configured to supply a key to the plate cylinder for soaking.
In the ink supply device of the plate printing device, Ink with an ink suction port located above the ink reservoir
Suction path, Different positions with respect to the axial direction of the ink suction port and the plate cylinder
An ink discharge path with an ink discharge port Ink wherein the ink suction path and the ink discharge path are connected
A circulation pump, An ink supply device for supplying printing ink to the ink reservoir;
And a device, The ink circulation pump supplies the printing ink in the ink reservoir.
Suction from the suction port and ink supply depending on the suction state
Ink pool by controlling the printing ink supply of the device
Characterized in that the amount of printing ink in each part is kept almost constant.
Stencil printing machine ink supply device. 3. The printing ink in the ink reservoir is provided with the ink
By suction path, ink circulation pump and ink discharge path
Ink supply pie separate from the ink circulation system formed
2. The hole according to claim 1, wherein the hole is supplied from a pump.
Ink supply device for plate printing equipment.